Book details
Summer of the Sea Serpent
The Magic Tree House, 2004 by Mary Pope
on Goodreads (6,771)
Description
Jack and Annie are off on another mythical mission at the request of Merlin the magician. Luckily, they have a young sorcerer, Teddy, to help them. From underwater caves to a Spider Queen, from mystical selkies to a magical sword, this is a Magic Tree House adventure kids won’t want to miss!